David Reger

The design of a novel concept for the synthesis of [3:2] pentakisadducts of fullerene C60 is presented. A sequential tether-directed remote functionalization approach is introduced for the construction of pentakisadducts. This fullerene derivative embellished with two different addends in two different directions can be considered as a valuable tecton for further functionalization. The stepwise cyclopropanation of C60 with a macrocyclic trismalonate and a bis(β-ketoester) yielded the corresponding pentakisadduct with an incomplete octahedral addition pattern. The reaction sequence gave access to two pairs of enantiomers that were easily separated by column chromatography on achiral stationary phase and characterized.

We demonstrate the benefits of using cofacial Zn–porphyrins as structural synthons in coordination-driven self-assembled prisms to produce cage-like singlet oxygen (¹O₂) photosensitizers with tunable properties. In particular, we describe the photosensitizing and emission properties of palladium- and copper-based supramolecular capsules, and demonstrate that the nature of the bridging metal nodes in these discrete self-assembled prisms strongly influences ¹O₂ generation at the Zn–porphyrin centers. The Pd^II-based prism is a particularly robust photosensitizer, whereas the Cu^II self-assembled prism is a dormant photosensitizer that could be switched to a ON state upon disassembly of the suprastructure. Furthermore, the well-defined cavity within the prisms allowed encapsulation of pyridine-based ligands and fullerene derivatives, which led to a remarkable guest tuning of the ¹O₂ production.

Get in tune: The benefits of using self-assembled cofacial Zn–porphyrin prisms as cage-like photosensitizers with tunable photosensitizing properties are reported (see figure).